Oil purifier



W. C. MCBAIN OIL PURIFIER v 2 Sheets-Sheet 1 Filed Feb. 3, 1933 I x i 1;;NTOR

@am wrm 'May 25, 1937. w. C. MCBAIN 2,081,632

OIL 'PURIFIER I Filed Feb. 3,y 1933 2 Sheets-Sheet 2 I ctrlglN'l-OR' 'Patented ltlay 25, i937 OIL PURIFIER William C. McBain, Youngstown, 0l1io, assigner to The Cold Metal Process Company, Youngstown, Ohio, a corporation of Ohio Application February 3, 1933, Serial No. 655,060

3 Claims.

My invention is concerned with the treatment of fluid for the purpose of removing suspended material therefrom -such as dirt and sludge. A particular application of the invention which will be described hereinafter is the use thereof for the treatment of lubricating oil in connection with any apparatus requiringv a continuous supply of fresh lubricant.

Numerous systems have been proposed heretofore for the treatment of used oil so as to recover the usable portion thereof. The prior methods with which l am familiar operate on the batch principle and are therefore objectionable since they do not provide a continuous supply of fresh oil. Another objection toprior devices of this hind is that special provision must be made for agitating ti e oil in the presence of a precipitating agent.

have invented a method and apparatus for treating fluids which overcomes the objections to the prior practices. In accordance with my inventlon, l collecty the fluid. to be treated in any suitable collecting chamber and deliver a pre cipitating agent to the chamber. A mixture of vthe :duide-nd the agent is pumped. from the col--r lecting chamber to a separating chamber. 'fue effect of the pumping operation is tocause a thorough mixture and agitation of the fluid and agent. "in the separating chamber, 'i provide means for drawing off the precipitating agent' from a point below the level thereof for redelivery to the collecting chamber. also provide means for drawing off the uid from the upper level thereof.

' a settling chamber is located below the separating chamber and is provided with a plurality of conical settling trays having apex holes therein, the edges of the trays being spaced slightly from the walls of the chamber. A downcomer traverses the trays and receives fluid from the separating chamber for delivery to the trays successively. conical sludge receiver is 4disposed below the trays and a suitable drain is connected thereto. Means are provided for heating the lower portion of the apparatus including the sludge receiver to insure uidity of the sludge collected therein. The uid rising to the top of the settling chamber has s bstantially the characteristics of fresh :duid and may be drawn off for delivery to the point of use.

For a complete understanding of the invention, reference is made to the accompanying drawings illustrating the present preferred embodiment, specifically applied to the treatment of lubricat- (Cl. 19E- 16) ing oil from machinery requiring a continuous supply thereof. In the drawings:-

F'igure 1 is a view partly in section and partly in elevation, showing the construction of the device whlch I prefer for carrying out the method of my invention and indicating diagrammatically the method performed; and v Figure 2 is a view partly in section and partly in elevation showing a slight modification.

Referring now in detail to the drawings a preferred embodiment of the apparatus for carrying out the method of my invention is indicated generally at lil. The apparatus comprises a settling chamber Il Vhaving a series of conical trays l2 supported therein in any suitable manner. The trays have apex openings lt. A conical sludge receiver lt is disposed inthe lower part of the chamber and communicates with a drain pipe l5 controlled by a cock lt. A heating coil il is disposed below the receiver Et and may be connected to anysuitable source of heating luid such as hot water or steam.

A dovmcomer extends from about the top 'of the chamber il down substantially to the receiver it. Sit has an enlarged mouth and a plurality holes 2E for discharging fluid, into the spaces between the trays. in offtalze El is mounted near the top of the chamber l l and has perforationsfor receiving fluid from the chamber for delivery to the point f .d gauge glass provides visible indication of the level of the huid in the chamber ll.

il separating chamber is mounted on top o' the settling chamber il by means of cooperating anges 25 on the top of the chamber li and the bottom of the chamber llt. surface discharge tube 2li extends through the bottom o the chamber 2t and to a point adjacent the top thereof. The chamber 'lf3 is positioned on the chamber ll so that the tube 2li and the downcomer i8 are in substantial alinement. l subi surface discharge tube 2l is mounted at one side of the chamber 2li. A screen filter 2,8 is located adjacent the top of the chamber 2t in position to receive vluid supplied through an inlet 2Q. The filter may be supported in any suitable manner for ready removal and dumping.

As an example of the use to which the invention may be put, l have illustrated it in connection with a cold strip mill a portion of which is shown at 3d. The machine has a hollow liquidtight base 3l -on which winding and unwinding drums 32 are mounted. These drums are driven in the known manner to draw lengths of stripl back and forth between the rolls (not shown) of the mill.

Lubricant for the bearings ofthe mill and for the strip being rolled isconducted fromI the upper portion of the chamber II by a pipe 33 connected to the oiftake 2|. It will be understood. of course, that the portion of the mill illustrated in the drawings is shown on a much smaller scale than the oil treating apparatus connected therewith. The latter,i'urthermore, will preferably be mounted above the equipment with which it is associated so that clean oil may ow therefrom to said equipment by gravity. In case such relation cannot be obtained, a pump may be employed for drawing the 4oil from the settling chamber and delivering it to the machinery for use. I have not shown the complete system f'or circulating oil to the bearings of the mill and the strip being worked therein since this forms nol part of the present invention.

A reciprocating pump 34 is mounted on the base 3| and is adapted to be driven by an eccentric 35 on the shaft of one of the drums 32. Any other type of pump or drive, of course, may be employed, depending upon the nature of a given installation. The pump 34 draws iiuid from the base 3| and delivers it through a pipe 36 to the inlet 29 of the separating chamber 24.

For treating oil in accordance with my invention, I prefer to employ an aqueous solution of soda ash, sodium bicarbonate, other compounds of sodium, or any alkali solution or other uiid having a coagulating or precipitating effect on the impurities in the oil. This solution is initially supplied to the separating chamber 24 in such quantity that the level there rises so that it will ow through a pipe 31 connected to the subsurface discharge tube 21, into the base 3| of the mill 30. The pipe 31 discharges into the base 3| below the level of fluid therein indicated at 38 so that a thorough mixture of the solution and the oil is eected.

It will be obvious that the fresh oil supplied to the mill, after lubricating the bearings thereof and the strip being rolled, is collected in the base 3|. The principal function of the alkali solution is to act as a precipitating agent. It causes the l ing rolled in the mill 34.

The pump 34 operates when the mill is running and delivers a mixture of the precipitating solution and oil through the pipe 36 to the inlet 23 of the chamber 24. It will be apparent that the pump serves effectively to :.agitate and mix the oil and the precipitating solution.

The mixture of the solution and oil is discharged through the chamber 24 into the 'screen lter 28 which removes the largest particles from the mixture. In the separating chamber,

the mixture of precipitating solution and oil tends to separate and form layers of solution and'oil indicated at 39 and 40 respectively. lSome of the sediment settles while the "oil-solution mixture is separating and such sediment can be removed at intervals from the chamber 2 4 by removing the cover. The solution in the neighborhood of the mouth of the sub-surface discharge tube 21 is practically clean and iiows through the pipe 31 back to the base 3|. t It will be noted that the discharge tube 21 is vented at 21a to prevent the siphoning of the contents of the chamber 24 into the base 3|.

Y spaces between the trays I2.

The tube 21 draws the precipitation agent from a location such as Ato insure the withdrawal of clean liquid only and allows only a limited amount of fluid to pass through the pipe 31 if the pump 34 or 46 is not in operation. 'I'he vent serves to prevent siphoning actionwhen the level of the liquid in separating tank 24 has dropped to the level of the connection between tube 21 and pipe 31. 'I'his automatically prevents the flooding of base 3| or sump tank 42 by the draining of tank 24 when the apparatus is shut down.

The oil rising to the top of the chamber 24,

when it reaches the level of the surface discharge' tube 26, flows downwardly therethrough into the downcomer I8. From the latter, the partially cleaned oil flows through the holes 20 into the The shape of the trays is such as to promote the settling of the sediment remaining in the oil. 'I'he sediment settles onto the trays and is directed downwardly toward the center of the settling chamber.

The cleaned oil rises and is guided toward the exterior of the chamber which affords a free path to the upper portionV thereof. The sludge collecting in the receiver ,I4 may be drawn off through the pipe I5 by opening the cock I6, and the heating coil I1 is employed to maintain the sludge in a fairly iiuid condition. The gauge glass 23 indicates the `level of the cleaned oil in the chamber II and a continuous supply may thus be maintained for. re-delivery tothe apparatus where the oil is used. An inner shell 4I between the Wall of the chamber II and the trays I2 prevents the oil in the central portion of the chamber from coming in contact with thev outer cock 43. Preferably the discharge end of the'A conduit 31 is spaced above the top of the tank 42 so that the continued iiow of the solution will be visible to attendants. A. branch 44 from the l conduit 31 is provided for supplying coagulating solution to the base 3|' of the machine 3|I under the control of a cock 45. The discharge end of the branch conduit is likewise spaced above the machine base 3|'. Cleaned oil is supplied to the machine through the conduit 33 as injFigure'l. The lmixture of lused `oil and coagulating solution is drawn from the tank 42 andA .delivered through conduit 36' to the separating chamber of the oil treating device by a pump indicated diagrammatically at 46, which may be driven by any convenient means.

The modification of Figure 2 has utility in cases where for one reason or another it is notl desirable or convenient tohandle the mixture of used oil andcoagulating solution in the machine base itself. The control cocks and the visible discharge of the coagulating solution may,

of course, also be incorporated in the system asshown in Figure I.

It will be apparent from the foregoingdescripcleaning of the oil at relatively little expense.

Y assises y The precipitating solution is used repeatedly and this contributes to further economy in operation. Since the pump for delivering the oil-solution mixture from the collecting chamber to the separating chamber eilects a thorou@ mixture and agitation thereof, it is not necessary to provide special means for this purpose in the body of the apparatus itself. The uid in the latter is always maintained quiescent and this aids the rapid settling of suspended particles.

In other words, it will be seen that my apparatus for treating oil consists'primarily of three parts: First, a simplied means for mixing a precipitating agent with the oil and raising same to an elevated position; second, means for salvaging the unused precipitating agent, and third, means for settling and removing precipitated foreign matter from the oil.

In addition to the above parts upon which my oil purier depends for normal operation, it will be noted that preferably I also use the vented suhmerged tube (2l, 21a., Fig. 1) for-withdrawing clean precipitation agent for reuse and for pre- Vventing the flooding of the collecting sump i2 (Fig. 2) or machine base (3|, Fig. l). This is preferably accomplished without manipulation of any valve on the part of the attendants. Additional apparatus in some cases may be added to the above and still come within the scope oi' my invention but it is the combination of these features as described that enables me to build an emcient,'economi cal oil purifier that is suitable for continuous operation. Y

Although I have illustrated and described the invention as applied to' the treatment of lubricating oil used in a rolling mill, it will be apparent that the invention is not limited to this application, but is useful for many other purposes.

Besides the treatment of lubricating oil, the invention is well adapted for removing suspended particles from other uids. The rolling mill partly illustrated herein is intended merely as an example of the use of the invention in cleaninglubricating oil for machinery requiring a conti/nuous supply thereof. It will be obvious that the invention will serve equally effectively to clean the oil supplied to any other type or machinery.

Although I have illustrated and described herein but one preferred embodiment of the invention. it will be apparent that numerous changes rating chamber to the in the method and atus disclosed may be made without departing from the spirit o! the invention as defined in the appended claims.

I claim:

1. An oil purifier for cooperation with an oil 1l: m I: device having a sump, comprising a treating tank, a conduit extending from a point adjacent the middle of -the tank to the consuming device for carrying puriiled oil from the tank thereto, a transverse partition in said tank above said conduit, a' conduit extending from a point below the top of the tenir to the sump for carrying an aqueouscoagulant iiuid from the tank to the sump, a conduit extending from the sump to' f a point adjacent the top of the tank for delivering to the latter a mixture of used oil and the coagulant, and means'for delivering oil from the upper part of the tank to a point adjacent said first-mentioned conduit.

2. A duid treating device, comprising upper and lower chambers, said upper chamber being adapted to receive for gravity separation a mixture of oli and a precipitating agent, means for drawing of; the precipitating agent from a layer formed in the upper chamber -from a point below the upper level oi' said layer, means for drawing od oil from the topdof said upper chamber and delivering it for settling to said lower chamber, a plurality of settling trays in said settling chamber, and a downcomer traversing the trays, adapted to receive oil from said last-mentioned means,

and extending downwardly from the top of the.

settling chamber, for delivering oil received from .the separating chamber to the trays, respectively.

3. The combination with an oil using apparatus including a chamber for collecting used oil, of means for delivering to said chamber an aqueous liquid for accelerating the precipitation of matter suspended in said oil, a pump connected to the chamber for withdrawing the contents thereof and mixing the liquid and the oil, an oil purifier connected to the pump having a separating chamber for receiving and separating the mixture delivered by said pump, said purliier also having a settling chamber for the removal of said suspended matter, means for delivering oil from the separating chamber to the settling chamber, and means for returning the liquid from the sepacollecting chamber. Y WILLIAM C. McBAIN.

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